QuakeIndex

Earthquake · reviewed by a seismologist

M 1.9md

Earthquake near Arroyo, PR

No earthquake was likely felt in Arroyo in the 24 hours to 11:29 am AST (15:29 UTC). The last one was M 3.3, 39 km (24 mi) WSW, at 8:40 am AST on 1 November 2026, estimated intensity II (weak) in town. Every earthquake near Arroyo

This page: a magnitude 1.9 earthquake was recorded 7 km (5 mi) south-southwest of Arroyo, PR, at 10:57 am AST on 23 August 2019 (14:57 UTC), 15 km deep.

USGS: 7 km SSW of Arroyo, Puerto Rico

55 km (34 mi) S of San Juan, PR · 37 km (23 mi) S of Caguas, PR

10:57 am AST, Aug 23, 2019 · · 15 km deep · released about 22 lb of TNT

Every earthquake near Arroyo Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Guayama Municipio 9 kmArroyo Municipio 9 kmPatillas Municipio 15 kmSalinas Municipio 19 kmCayey Municipio 23 kmMaunabo Municipio 23 kmSan Lorenzo Municipio 29 kmYabucoa Municipio 30 kmCidra Municipio 31 km
Distance rings around the epicentre, with the nearest towns at their true direction and later quakes as coloured dots. Not a shaking map — see the USGS ShakeMap for that.
When
10:57 am AST on 23 August 2019 ()
Where
7 km (5 mi) south-southwest of Arroyo, PR · earthquakes near Arroyo
Magnitude
M 1.9 (md)
Depth
15 km below the surface
Felt
no reports yet
Nearest
Guayama Municipio, 9 km NNW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2637 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

At this magnitude and depth it was probably too small to be felt, even directly above it. In Arroyo, 7 km away, the estimate is intensity II (weak). Estimated from magnitude, depth and distance with the intensity equation USGS Did You Feel It? uses; felt reports, where there are any, are the measurement.

Earthquakes near other towns within 30 km: Guayama, Jobos, Corazón, Olimpo, Buena Vista, Palmas.

How big was it?

This earthquake released about 22 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.9 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 680,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 480,000× the energy of this one
  3. Around the size people start to feel M 3.0 43× the energy of this one
  4. This earthquake M 1.9 about 22 lb of TNT

Energy from the Gutenberg–Richter relation (log10E = 1.5M + 4.8), rounded to two figures; bar length is magnitude, which is already a logarithm of energy. Magnitudes of past earthquakes from the USGS catalogue.

For this area

The largest earthquake within 50 km since 2016 was M 4.6 on 2016-12-05 — about 11,000 times the energy of this one.

Before 2016, the USGS record lists one earthquake of M5 or more within 50 km:

  1. 5.1 3 km W of Aguas Buenas, Puerto Rico · 39 km N of this epicentre

Since 2016: the QuakeIndex catalogue (US, M1.5+), built from the USGS FDSN event service. Before 2016: USGS ComCat, M5+ from 1900. Distances are between epicentres. This is the record, not a forecast.

Where

Epicentre 17.9078, -66.0935. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Guayama Municipio, PR 9 km (5 mi) NNW earthquakes near Guayama Municipio
Arroyo Municipio, PR 9 km (6 mi) NE earthquakes near Arroyo Municipio
Patillas Municipio, PR 15 km (9 mi) NE earthquakes near Patillas Municipio
Salinas Municipio, PR 19 km (12 mi) WNW earthquakes near Salinas Municipio
Cayey Municipio, PR 23 km (14 mi) NNW earthquakes near Cayey Municipio
Maunabo Municipio, PR 23 km (14 mi) ENE earthquakes near Maunabo Municipio

Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.

Aftershocks so far

38 earthquakes have been recorded within 50 km since this one.

  1. 1.6 2 km SE of El Ojo, Puerto Rico
  2. 1.9 11 km SSW of Potala Pastillo, Puerto Rico
  3. 1.7 1 km W of Jauca, Puerto Rico
  4. 2.1 0 km N of Salinas, Puerto Rico
  5. 2.3 10 km S of Salinas, Puerto Rico
  6. 2.2 4 km ESE of Bayamon, Puerto Rico
  7. 1.6 10 km SSW of Potala Pastillo, Puerto Rico
  8. 1.8 28 km SE of Emajagua, Puerto Rico
  9. 1.8 27 km SE of Emajagua, Puerto Rico
  10. 1.6 2 km NNW of Jagual, Puerto Rico
  11. 1.8 28 km SW of Esperanza, Puerto Rico
  12. 1.6 1 km NNE of Parcelas Nuevas, Puerto Rico
  13. 1.9 26 km ESE of El Negro, Puerto Rico
  14. 1.7 25 km SE of Emajagua, Puerto Rico
  15. 1.7 26 km SE of Emajagua, Puerto Rico

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of . QuakeIndex does not forecast aftershocks. When USGS issues an operational aftershock forecast it appears on the USGS event page.

On USGS

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.